This guy just didn't feel like dealing with it.

This guy got bored.

Interesting enough to start something with, not very interesting once it gets going. There's no ill-will so you don't want to 'break' the relationship but your [sic] not motivated to maintain it, so you just fade away.

This guy saw it as the only way to actually cut her out.

This guy thought she was flirting with other guys.

It wasn't so much of hurting her but really looking out for myself....she was entertaining other dudes into thinking they had a chance with her so I made it easier for them. She's a smart girl and caught on quickly that we wasn't [sic] dating anymore once she stalked my facebook page and saw no evidence of "us". She texted "you're a fucking asshole"....nope just a product of my environment